Cylinder mechanism for molding machines



July 1, 1969 E. c. MEDILL CYLINDER MECHANISM FOR MOLDING MACHINES SheetFiled July 18, 1966 INVENTOR. EDWIN C. MED! LL July 1, 1969 E. c. MEDILLCYLINDER MECHANISM FOR MOLDING MACHINES Sheet 2 of 5 Filed July 18, 1966INVENTOR. EDWIN c. MED! u. wafla z July 1, 1969 c, LL, 3,453,656

CYLINDER MECHANISM FOR MOLDING MACHINES Filed July 18, 1966 7 Sheet 3 of3 INVENTOR. EDWIN C. MED! LL k/M/ W US. Cl. 164-212 4 Claims ABSTRACT OFTHE DISCLOSURE A piston and cylinder combination :for multiplying forceswherein one cylinder is telescopically received in the other. A pistonis slidably received in the inner cylinder and the piston is fixed tothe outer cylinder. A pipe extends through the inner cylinder into aspace between the inner cylinder and the outer cylinder to supply airunder pressure to this space. An opening in the pipe admits air into theinner cylinder between the piston and the inner cylinder, and an exhaustpipe is connected to the space between the inner cylinder and the outercylinder on the remote side of the piston from the space that receivesair from the opening in the pipe.

This invention relates to molding machines and, more particularly, tomeans for compressing sand in a molding machine.

In the green sand foundry industry, there is a common type of moldingmachine wherein the sand is squeezed in fiasks around a pattern.Sometimes this molding machine utilizes a hydraulic cylinder to exertthe pressure on the sand. It has been discovered that by providing acylinder that multiplies the pressure air already available at themolding machines, it is possible to compress the sand by means of air inthe cylinder and to dispense with the hydraulic cylinder. This therebyeliminates the need of a hydraulic system on the machine.

It is, accordingly, an object of the present invention to provide animproved molding machine.

Another object of the invention is to provide an improved means tocompress sand in a molding machine.

Still another object of the invention is to provide a molding machinewhich is simple in construction, economical to manufacture, and simpleand eflicient to use.

With the above and other objects in View, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawings and moreparticularly pointed out in the appended claims, it being understoodthat changes may be made in the form, size, proportions, and minordetails of construction without departing from the spirit or sacrificingany of the advantages of the invention.

In the drawings:

FIG. 1 is a front view of a molding machine according to the invention;

FIG. 2 is a side View of the machine shown in FIG. 1;

FIG. 3 is an enlarged view partly in cross section showing the improvedpiston and cylinder combination;

FIG. 4 is a schematic view of the piston and cylinder combinationshowing the piston and cylinder before air is admitted thereto;

FIG. 5 is a view similar to FIG. 4 showing the combination withcompressed air inserted into the chambers and the piston and cylinderextended relative to each other; and

FIG. 6 shows the piston and cylinder combination of FIGS. 4 and 5 duringthe retraction part of the cycle.

Now with more particular reference to the drawings,

United States Patent 0 3,453,656 Patented July 1, 1969 the moldingmachine shown in FIGS. 1 and 2 has a frame 10 that has a conveyor 11suitable to support a flask 12. The frame supports a squeeze board 13. Asupply of compressed air is provided thru the valve mechanism 14 whichis connected to the pipes E and D in a suitable manner.

The piston and cylinder combination '15 is supported on the machineframe and supports the squeeze unit which is a piston and cylindercombination rigidly and provides a reaction member for supplying areaction force on the squeeze unit during the time the sand is beingcompressed.

The first cylinder 17 has a closed top and wall as indicated. The closedtop 18 has a piston rod 19 fixed to it which extends down through theclosed top 20 of the second cylinder 21 and has a sealing washer 22disposed in a groove around the outer periphery of the piston 23 whichmakes sealing engagement with the inside of the cylinder 21. Likewise, asealing ring 24 is disposed in the internal peripheral groove in thecylinder 17 whch makes sealing engagement with the outside surface ofthe cylinder 21. Thus, the piston 23, along with the inside of thecylinder 21 and the bottom, forms a second chamber C while a firstchamber A is formed as shown.

High pressure may be admitted through the pipe D which escapes into thesecond chamber through the opening 28 and escapes into the first chamberfrom the end at 29. The air is exhausted through the pipe E from chamberC. Thus, the force of air in the first chamber A is exerted on theclosed top 18. The force of the air in chamber C is added to the firstmentioned force directly since it is transmitted from piston 23 throughpiston rod 19 to the closed top 18 which would react on the sand tocompress it.

The squeeze unit is shown in more detail in FIG. 3 and it will be notedthat air will be admitted to chamber C from pipe D and through theopening 28 into the pipe shown and out the end 29 to the chamber A. Airwill be exhausted from the two chambers in a like manner in a reversedirection through pipe 19 and pipe E.

Thus, the efiect of air pressure will be in substance doubled by thearrangement of cylinders in the squeeze unit.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood is broadly novel as is commensurate with theappended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A piston and cylinder combination for multiplying forces in moldingmachines comprising a first cylinder and a second cylinder,

said first cylinder and said second cylinder each having a side wall anda closed end,

said second cylinder being telescopically received in said firstcylinder,

means forming a seal between the walls of said first cylinder and thewalls of said second cylinder whereby a chamber for fluid is formed bythe inside of said first cylinder and the outside of said secondcylinder,

a piston rod attached to said first cylinder and extending through saidsecond cylinder and into said second cylinder,

a piston attached to said piston rod,

said piston slidably engaging the inside of said second cylinder,

closing means closing the end of said second cylinder whereby a secondchamber is formed by said second cylinder, said piston, and said closingmeans,

and means to admit fluid under pressure into said first chamber,

and means to admit fluid under pressure into said second chamber,

said means to admit fluid under pressure comprising a single conduitconnected into said second chamber and through said piston into saidfirst chamber,

said conduit having means to admit fluid thereinto to exhaust fluid fromsaid first chamber and from said second chamber.

2. The piston and cylinder combination recited in claim 1 in combinationwith a molding machine having a frame,

said molding machine having means thereon to support a flask with sandtherein,

said piston and cylinder combination being supported on said frame,

and means on said piston and cylinder combination adjacent said flaskfor engaging said sand and adapted to compress said sand when fluidunder pressure is admitted into said chambers.

3. The combination recited in claim 11 wherein said conduit meanscomprises an exhaust pipe extending through said closing means into saidsecond chamber and further extending through said piston andcommunicating with said first chamber,

a pressure pipe communicating with said first chamber and said secondchamber,

said exhaust pipe and said pressure pipe extending through said piston,

and sealing means between said piston and said pressure pipe and betweensaid piston and said exhaust pipe slidably engaging said pipes wherebysaid piston may slide relative to said pipes.

4. The piston and cylinder combination recited in claim 3 in combinationwith a molding machine,

said molding machine having a frame,

and means on said frame to support a flask with sand therein to becompressed,

said piston and cylinder combination being supported on said frameadjacent said sand,

said piston and cylinder combination being adapted 15 to engage saidsand to compress it.

References Cited UNITED STATES PATENTS I. SPENCER OVERHOLSER, PrimaryExaminer.

E. MAR, Assistant Examiner.

25 US. Cl. X.R.

